In the image below, when the switch is closed (and when it's opened again), the video has a severe flicker. It only does this when the switch is changing states. While the load is on, the video returns to normal. I've been trying for a week to figure out how to get rid of it. Here is some scope data that may help someone more experienced than I.. Any help would be greatly appreciated

Your picture only shows a single connection for the video, so presumably it's using the common earth. That suggests that the two wires carrying the video signal may not be close together. You might try taking the video and earth to the camera via a shielded twisted pair cable (with the shield grounded at one end) and see if that reduces the amount of EMF picked up on the video channel.

I only provide help via the forum - please do not contact me for private consultancy.

They are in their stock housing coming out of the camera, then they are apart for about half an inch as they go into a cat5 breakout board, then they are in a twisted cat5 pair for 8ft or so, then the reverse happens as they go into the LCD screen at the other end.

I have an idea of what might be happening, if thought of like a Y connection in a water pipe, when the the high amp load is turned on all of the water (amperage) flows into it temporarily depriving the camera and causing the brief loss of video. Once the motor's on, the current flow stabilizes and the video is clear again while the motor is powered. Is that what's happening? if so, how do you make sure the camera will always have the current and voltage it needs to operate smoothly? Use an inductor?

They are in their stock housing coming out of the camera, then they are apart for about half an inch as they go into a cat5 breakout board, then they are in a twisted cat5 pair for 8ft or so, then the reverse happens as they go into the LCD screen at the other end.

What size wire is used between the 12v battery and the 4a load, and how long is that wire?

It is just whatever thickness is usually used in PC power supplies. Then it goes into a solid copper cat5 cable and back to pc power supply wire. From there it is soldered to the thicker pigtails wires that came with the 4amp motor.

just one is ground, one is 12v+ that powers the camera, one is the power for the 4amp load, one is +video, and the other four are going to two bi-directional motors which, by the way, have no effect at all on the video when used.

These graphs are before and after adding a cap across ground and load+. I also tried other cameras, and powering those other cameras with a completely independent power supply (same results). Maybe the cap increases the current draw because the power supply has to suddenly charge the cap and power the load.